[9fans] servers that rewrite QID

[9fans] servers that rewrite QID

[ron minnich]

[-- Attachment #1: Type: text/plain, Size: 399 bytes --]

a few years back, there was a 9p server (or servers) that, for $REASONS$,
would rewrite QIDs as part of supporting Twalk.

If this seems familiar to you, let me know.

------------------------------------------
9fans: 9fans
Permalink: https://9fans.topicbox.com/groups/9fans/T96770ff52e2ab242-M0784d6142543b950062d54a5
Delivery options: https://9fans.topicbox.com/groups/9fans/subscription

[-- Attachment #2: Type: text/html, Size: 892 bytes --]

Re: [9fans] servers that rewrite QID

[Ori Bernstein]

On Fri, 6 Feb 2026 19:55:10 -0800
ron minnich <rminnich@gmail.com> wrote:

> a few years back, there was a 9p server (or servers) that, for $REASONS$,
> would rewrite QIDs as part of supporting Twalk.
> 
> If this seems familiar to you, let me know.
> 

exportfs, see io.c:419/^uniqueqid

this is because while a qid is defined as unique within
a file server, it may be (and often is) reused across
them; see, for example, enum { Qroot, Qdir, Qthing} in
many many devices and file servers.

-- 
Ori Bernstein <ori@eigenstate.org>

------------------------------------------
9fans: 9fans
Permalink: https://9fans.topicbox.com/groups/9fans/T96770ff52e2ab242-Mefc1704a9c9d43bda06e7aa2
Delivery options: https://9fans.topicbox.com/groups/9fans/subscription

Re: [9fans] servers that rewrite QID

[Dan Cross]

On Sat, Feb 7, 2026 at 5:46 AM ron minnich <rminnich@gmail.com> wrote:
> a few years back, there was a 9p server (or servers) that, for $REASONS$, would rewrite QIDs as part of supporting Twalk.
>
> If this seems familiar to you, let me know.

I wonder if you're thinking of "A Cache to Bash for 9P" by Collyer and
Forsyth. http://www.collyer.net/who/geoff/fscfs.pdf

        - Dan C.

------------------------------------------
9fans: 9fans
Permalink: https://9fans.topicbox.com/groups/9fans/T96770ff52e2ab242-M0ce4cc5d22516ac8c01a44ce
Delivery options: https://9fans.topicbox.com/groups/9fans/subscription

Re: [9fans] servers that rewrite QID

[kvik via 9fans]

> If this seems familiar to you, let me know.

I've done it in unionfs for the same reason it's done in exportfs.

Unionfs does some semi-clever filtering in front of the Qid map because
I found the map was using half a dozen megabytes of memory which I couldn't
abide at the time.

Here's that:

https://raw.githubusercontent.com/okvik/unionfs/refs/heads/master/qmap.c

------------------------------------------
9fans: 9fans
Permalink: https://9fans.topicbox.com/groups/9fans/T96770ff52e2ab242-Ma5d35d68488ea459df5c9365
Delivery options: https://9fans.topicbox.com/groups/9fans/subscription

Re: [9fans] servers that rewrite QID

[ron minnich]

[-- Attachment #1: Type: text/plain, Size: 1008 bytes --]

you folks might enjoy this

https://github.com/hugelgupf/p9/pull/104

fixes a real problem in a real place.

ron

On Sat, Feb 7, 2026 at 3:09 AM Ori Bernstein <ori@eigenstate.org> wrote:

> On Fri, 6 Feb 2026 19:55:10 -0800
> ron minnich <rminnich@gmail.com> wrote:
>
> > a few years back, there was a 9p server (or servers) that, for $REASONS$,
> > would rewrite QIDs as part of supporting Twalk.
> >
> > If this seems familiar to you, let me know.
> >
>
> exportfs, see io.c:419/^uniqueqid
>
> this is because while a qid is defined as unique within
> a file server, it may be (and often is) reused across
> them; see, for example, enum { Qroot, Qdir, Qthing} in
> many many devices and file servers.
>
> --
> Ori Bernstein <ori@eigenstate.org>
>

------------------------------------------
9fans: 9fans
Permalink: https://9fans.topicbox.com/groups/9fans/T96770ff52e2ab242-M3cd4f876ac0fdad8e3bebc8c
Delivery options: https://9fans.topicbox.com/groups/9fans/subscription

[-- Attachment #2: Type: text/html, Size: 2131 bytes --]

Re: [9fans] servers that rewrite QID

[sirjofri via 9fans]

07.02.2026 17:08:04 ron minnich <rminnich@gmail.com>:
> you folks might enjoy this 
> https://github.com/hugelgupf/p9/pull/104

I already enjoy the name of the user.

sirjofri

------------------------------------------
9fans: 9fans
Permalink: https://9fans.topicbox.com/groups/9fans/T96770ff52e2ab242-M586634d8fcdc5105d987cf71
Delivery options: https://9fans.topicbox.com/groups/9fans/subscription